Choose one:
1. How are we changing the physical environment of Earth’s surface?
2. How can we best preserve biological diversity and protect endangered ecosystems?
3. How are climate and other environmental changes affecting the vulnerabilities of coupled human-environment systems?
4. What is the capital of Tajikistan?
5. Where and how will 10 billion people live?
6. How will we sustainably feed everyone in the coming decade and beyond?